Oh, wow ... i tried it and it is indeed much more useful than i expected it to be. Great!

There are two issues with Harmattan which also arise under Symbian and which i therefore had to implement a solution for. Perhaps you want to re-use these:

• Symbian also has no controls to close full screen windows. To cope with this the customwindow.cpp contains some magic to implement a custom window title with icon and a "back" arrow in the top right corner.
• Symbian doesn't support finger/touch scrolling by itself. This is implemented in flickcharm.cpp (inspired by but not identical to a similar solution from nokia). Just enable the flickcharm section in the pro file and finger scrolling should be possible in most lists

Also you might consider removing the non-fullscreen mode entirely as it doesn't seem to make much sense on harmattan and the button just eats up screen space.

CacheMe 0.8.12 is out and e.g. addresses the map arrow heading in the main map. It's now bound to the magnetic compass and always points in the right direction.